Usually in the first year, basics of Thermal Physics, Classical mechanics, Electronics, Waves and Optics and Mathematics are involved in the syallbus. So you don't need to go for any difficult or high standard reference books. If you start with a simple one, it would be better for you. And can increase the level as you promote to the next level. Books like Modern Optics by AB Gupta, ELECTRONIC device and Circuit Theory by R Boyelstad and Nashelsky, Classical Mechanics by Goldstein, Schaum's Outline Series- McGraw Hill, Heat and Thermodynamics by Zemansky and Ditman etc.